In typical fluid line assemblies, mechanical nuts may be used to couple together fluid lines or to couple fluid lines to fluid sources or outputs. The nuts are typically preassembled on the fluid line before the fluid line ends are flared. As such, bend radii in the fluid line may be limited to allow the preassembled nuts to slide on the fluid line to reach either fluid line end. Moreover, a minimum amount of length is typically left on each fluid line end to allow tube flaring tools to flare the fluid line ends without being obstructed by the preassembled nuts. When building fluid line assemblies in limited volumetric areas (e.g., in aerospace applications), tube bend radii and shapes may be hindered, thus resulting in longer tube lengths, larger tube bend radii, and less optimization of the fluid line assembly.